Well youre talking about mathematical stuff which I let go over my head years ago. :P Fair enough; I defer to those with higher skills than myself. I spose nows not a good time to mention im job hunting? :P Anyone need a Senior Helpdesk or Junior NOC type person? ... *shrug* :) Mark. At 09:55 14/08/2001 +1200, Matthew G Brown wrote:

All loss can be calculated . ( Within reason )

The exact frequency of the ISM band channel is avai on manafacture WWW sites.

Cable Loss - http://www.timesmicrowave.com ( If your a LMR person ) Connector Loss - http://www.tessco.com or http://www.timesmicrowave.com * NB: I use Shuners conenctors over Times anyday Insertion Loss - See Antenna manafacture

Free Space Loss (isotropic):FSL (isotropic) = 20Log10(Frequency in MHz) + 20Log10 (Distance in Miles) + 36.6

Then you can check your operating margin, I run with 10db+ anything less and you asking to get your head run over by a bare naked lady

SOM = RX Signal Level - RX Sensitivity

RX Signal Level = TX Power - TX Cable Loss + TX Antenna Gain - FSL + RX Antenna Gain - RX Cable Loss

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